Civil Engineering Association

WIND FLOW CHARACTERISTICS AND THEIR EFFECTS On Low_Rise Buildings - Phd

Two fundamental flow phenomena, the separation bubble (SB) and conical vortex~
over the roof (flat and rectangular) of the Texas Tech test building are studied in terms of
flow characteristics and pressure-generating mechanisms. Major fmdings contribute to
understanding the mechanisms of pressure generation and the roles of turbulence and
other properties of the incident wind in loading effects.
Much of the debate on wind-tunnel simulation priority in the wind engineering
community has failed to distinguish the different effects the incident wind has on two
types of quantities: single events, e.g., minimum (peak) pressures, and statistics~ such as
the mean and the rms pressures. The turbulence intensities, reflecting the gust structure
and the directional fluctuations of the free-stream wind, might bear significant influences
collectively on the pressure statistics. It is the intensity of individual longitudinal gusts
(as well as the incident wind angles) that decides the data-run-wise peak-pressure
coefficients on the roof corner~ while the peak-pressure coefficients associated with the
SB are governed by the lateral directional fluctuation in the incident wind. Proper
simulation of the incident wind profile (boundary layer type) is probably the most
important single input in the wind- structure interaction process.




OCR Version